Superconductor Precursor Example

These sets of images are small (64x64) quantitated (JEOL) electron probe
maps of ceramic superconductor precursor material. The material has several
distinct phases which are seen in the maps, and more clearly seen in color
overlays and scatter diagrams.

Load the images.

MLx -> Image Files -> TIFF -> Read Multiple

Unlike most other image processing programs, MacLispix must be told
what type of file it is to read.

The images can be loaded separately using MLx -> Image Files
-> TIFF -> Read, but it is much easier to handle them as a group.

Find Demo_Images / Super cond maps/ Set 2/ *.tiff

Select one of the tiff files as a sample. A dialog showing all files
in the folder with the same extension.

In the next dialog, select all of the images except the total image
by:

Click the Select All button.

Command-clicking the total.tiff file.

Click the Load button.

The postage stamp sized images will be stacked on top of each other
and will look like this:

Only one of the maps is visible

The window is too small to read their names.

Selecting the W menu with the option key held down will show all of
the images in a menu. Selecting one of them will bring that image to the
front, thereby selecting it. Lines will appear in the title bar.

Information on the windows can be listed in the Monitor window. Get
the Mlx Buttons window using the MLx -> Buttons
menu. The Info... button in
the Images collumn has two options. Select one, then click on the Monitor
window to see the results.

Although the regions of different phases (compositions) can be determined
by examining the images separately, RGB color overlays make the regions
stand out at a glance (Bright 1990, 1991)

Other Windows -> Multivariate Makes a new button window for
the following steps:

Select the red, green and blue images

X/Red Image -> CBI... Choose the Bismuth image to be shown
in red.

Y/Green Image -> CCA... Choose the Calcium image to be shown
in green.

X/Red Image -> CBI... Choose the Copper image to be shown
in blue.

The upper left part of the Multivariate Buttons window will then
look like this. The image names replace the original button names.

The RGB overlay requires three gray level images of the same dimensions
(but not necessarily of the same pixel type or intensity range. The overlay
is made from the scaled images, which are always unsigned 8-bit images.)
After selecting one image, only those images of the same size as the other
two will be presented for selection.

Make the RGB Overlay... RGB Overlay...->make

Zoom the overlay by ...

Using the zoom button as before

Dragging the grow square.

This overlay was zoomed by x1.5 using the zoom menu in order to
make it the same size as the others.

There appear to be four phases present.

Scatter Diagrams

Another way to see how many phases there are, and quantify them as well,
is to use scatter diagrams (see introduction).
Using the three images already selected for the color overlay (also see
Kowala example)

2d xy...->normal

Click on the slider to 'thermalize' the image as desired.

Axes makes the axes shown the concentration values (in this
case) x100 for the clusters. The clusters correspond to the different phase.

To see what regions of the images correspond to the features of this
scatter diagram, see traceback 1.

3D xyz...->normal

Rotate the cube window to some orientation similar to this one by dragging
the mouse across it.

X, Y and Z are Bi, Ca and Cu respectively (see the ccch title bar).

Axis labels are not available for the three - dimensional scatter diagram.

2-D Traceback #1

The traceback command makes a color labeled image (a traceback map) corresponding
to the original images. The color for any pixel is the (automatically assigned)
color of the parallelogram shaped region that encloses the corresponding
point in the scatter diagram.

Select regions in the scatter diagram using the traceback...->normal
button.

A pink info line will appear across the top of the scatter diagram.

For each parallelogram

Drag one side.

(mouse up)

Drag that side parallel to itself to 'fatten' it into a parallelogram

Click the small square 'go away' button on the pink line when done.

Note: when making the parallelograms, you may drag off the image. That
is ok. Regions outside the image are ignored.

After closing the pink info line, the traceback mask (zoomed here)
will appear.

Note how the regions (but of course not the colors) roughly correspond
to the pastel colored regions in the color overlay.

This is a 'palette' window. It labels the colors of the parallelograms
in the scatter diagram and the colored regions in the mask. Option-clicking
a color or a label allows you to change it.

Traceback - Three Dimensional

Traceback for the three-dimensional scatter diagrams is identical to
that of the two dimensional diagrams. Regions are selected by 'mousing'
parallelograms. The selected points appear inside the parallelogram -- physically,
they are in a parallelopiped seen end-on. I have not implemented graphics
to show side views of the selection region by rotating the scatter diagram.
Once the diagram is rotated, the selection regions are not valid.

Try different views of the 3-D scatter diagram to make sure that unwanted
bins are not selected because they are along the line of sight of desired
bins.

About the Data

The data were taken by Ryna B. Marinenko, NIST, Gaithersburg, Md. and
by Slavko Bernik, currently at the Jozef Stefan Institute, Ljubljana, Slovenia.
(see references by Marinenko and Bernik)

The pixel values are weight percent x 100 (the images are 16 bit integers),
except for the total map which is percent x 10.

Dwell time: 2 secs/pixel

Field of view: 50µm on a side, roughly.

Magnification: 1700x mag. - expect some defocusing.

Beam: 70 nanoamps, 20 Kv.

Sets 1 and 2 - mixed phases .Set 3 - appears to have only one phase -
the desired superconducting phase, The broadening of the ratio of (Bi+Pb)/(Sr+Ca)
is probably due to self shielding in the e-probe.